Tanning brand St Tropez who undertook the research said two thirds of women have a "slump in energy levels" by mid-afternoon on a Wednesday, forcing many to reach for a sugary snack.

The good news? Those surveyed said Thursday is also the day they are most likely to have sex. This may be one reason why 60 per cent of those surveyed nominate Friday as their happiest day.

The mid-week slump appears to hit many women hard with one in five working through their lunch hour on a Wednesday while a quarter get stressed several times a week.

"It's fascinating that 3.30pm on a Wednesday is the time women look their oldest,"St Tropez spokesperson Nichola Joss Told Britain's Daily Telegraph.

"Combine the highest stress levels of the week on a Wednesday with the natural mid-afternoon slump and it seems that's why women can look older than their years."

The visual effects of drinking at the weekend may also begin to show mid-week, Ms Joss said adding that many women struggle to get good sleep at the start of the week and many abandon their skin-care regime on a Wednesday.

The research was carried out to coincide with the launch of St Tropez Gradual Tan Plus Anti-Ageing Face lotion which may have some questioning its validity.

So women of Australia - how well do you scrub up at 3.30pm on a Wednesday? Send us images of yourself or your girlfriends here or tag images with #330Wednesday on social media.

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